1. Field of the Invention
The present invention relates to an image forming apparatus that stores plural print jobs, a control method and a program thereof.
2. Description of the Related Art
There has been a technology that, in order to reduce power consumed by a printer device, a print job received from a host computer is held once in the printer device and then, a plurality of held print jobs are printed and processed altogether (See Japanese Patent Laid-Open No. 2004-284281). Also, there is a technology that, in order to keep secret of a print document, print processing is not started immediately after the printer device receives a print job. That is, there is a technology that immediately after the reception of the print job, only analysis or rendering processing of the print job is performed, and if authentication is obtained by an authentication operation of password input by a user and the like in the printer device, the printing processing on a recording paper is performed (See Japanese Patent Laid-Open No. 2002-187317). As mentioned above, there is a printer device that stores a print job received from a host computer once in the printer device and does not start printing processing immediately.
On the other hand, there is a printer device that corrects a change in an output image involved in a change of an environment such as a temperature, humidity and the like and corrects density in order to supply stable images. Also, in the case of an electrophotographic printer device, density correction is made in order to correct a change/deterioration in a visible image involved in deterioration of consumable supplies such as a photoconductive drum, toner of a toner cartridge and the like and to supply stable images. The print job received in Page Description Language (hereinafter called “PDL”) is subjected to rendering processing in a print device in general, and continuous-tone bitmap is generated. Then, bitmap data for printing subjected to the above-described density correction processing (half-tone bitmap, for example) is generated, and printing on a recording paper is performed on the basis of this bitmap data for printing.
As a technology to improve performance of the printing processing considering the above density correction, a technology in Japanese Patent Laid-Open No. 2002-137462 is proposed. According to the proposal of Japanese Patent Laid-Open No. 2002-137462, instead of generation of bitmap data for printing from PDL for each printing processing, PDL and the bitmap data for printing generated in advance are both prepared. Then, a print device is proposed that, till the density correction processing is newly required, the bitmap data for printing is used, while if the density correction becomes necessary, the bitmap data for printing is generated again from the PDL.
However, if the technology described in Japanese Patent Laid-Open No. 2002-137462 is to be applied to a method of storing a job in a printer device once as disclosed in Japanese Patent Laid-Open No. 2004-284281 or Japanese Patent Laid-Open No. 2002-187317, the following problem would occur. That is, since the PDL and the bitmap data for printing need to be held for all the print jobs stored in the print device, a large capacity is required for a storage device. Moreover, if the density correction processing becomes necessary, the PDL of all the print jobs need to be rendered again. Since time required for the rendering processing is different depending on the image, waiting time for rendering is generated, which results in deterioration of print performance.